The present invention relates to a gas metering valve having at least one valve seat and at least one closure member which can be pressed against the valve seat, wherein the closure member in a maximum open position is raised at least in regions from the valve seat and in a maximum closed position is pressed against the valve seat, wherein the gas metering valve has an adjusting device which is spring-loaded by means of a spring loading device of the gas metering valve for adjusting the closure member in a closing direction from the maximum open position into the maximum closed position.
Generic gas metering valves are used above all in so-called vacuum technology where technically demanding production processes run in an artificially realized, extensively gas-free chamber. The generic gas metering valves are required, for example, for the purpose of actively supplying a precisely metered amount of a gaseous reaction partner during a production or further processing process or of holding the pressure in the closed reaction chamber at a predetermined level. As a result of said problem definition, said gas metering valves, on the one hand, still have to close reliably and in a permanently metallic sealing manner even in the region of very high negative pressure and, on the other hand, still have to enable fine metering of gases under these conditions. This results in very high demands for precision during the manufacture of the gas metering valves.
A generic gas metering valve is known from U.S. Pat. No. 4,903,938. The disadvantage of the valve shown there, however, is that it is very susceptible to temperature.